"There is no doubt that when they are on the front foot they are a very impressive side," said McGeechan who will also be keeping an eye on the performances of each of the Home Nations this autumn.
"I think that they are still putting their game together but they have got a good front five, they have got one of the strongest second row pairings in world rugby and they have got a back row where they can choose from probably five really top-class players.
"You are talking about a forward pack that is big and competitive and then you have backs who can use that ball one on one and who are very dangerous players."
Having already disposed of Wales, Peter de Villiers' side travel to Scotland and England on successive weekends as they continue their build up to next year's Lions tour. Scotland are next to host the Boks at Murrayfield on Saturday afternoon and McGeechan is expecting his countrymen to rise to the occasion.
"The Springbok back row is very competitive and I think that Scotland as they played at the weekend also have a very good back row," added McGeechan.
"I think that will be a challenge for them. It is these sorts of games that Scotland need to play because these are the games that do lift you a level.
"I know that in my early days as Scotland coach, which was back in the mid-eighties, we made an effort to tour New Zealand on a regular basis and to go there as often as we could when nobody else was doing so because it was the best practice that you could get for knowing the level at which you needed to perform. "
Scotland versus South Africa kicks off at 2.30pm this Saturday, November 15.